Meat for use in making hamburger patties or the like is ordinarily provided in the form of large frozen blocks. In the prior art machines and methods for forming patties the frozen blocks of meat are broken up into smaller pieces which are then cut into flakes and warmed to 30.degree. F. or higher before being introduced into the supply hopper of the patty-forming machine. The warming of the frozen meat flakes has been considered necessary to render the meat sufficiently soft or plastic to be handled by the machine and formed into cohesive patties.
A particularly advantageous patty-forming machine is described in the Orlowski U.S. Pat. No. 4,065,241 and comprises a power driven turret mounted for rotation on a vertical axis with a plurality of patty-forming molds being provided on the turret. Each mold comprises a bottom opening cavity in the turret and a piston mounted for reciprocation in the cavity in timed relation to the rotation of the turret. As the turret rotates, each mold is moved past a stationary feeding mechanism where meat from a supply source is forced into the mold cavity as the piston moves upwardly in the cavity. As the turret continues its rotation, the piston is moved downwardly in the cavity and the formed patty is ejected from the mold at a location substantially 180.degree. away from the feeding mechanism. A patty separating device in the form of a continuous moving cut-off band is positioned at this location and effects separation of the formed patty from the bottom surface of the piston. The separated patty is then deposited on a moving conveyor.
In the aforementioned Orlowski U.S. Pat. No. 4,065,241 the feeding mechanism comprises a housing containing a pair of augers which feed the meat upwardly through an opening in a horizontal retaining plate which communicates with each mold opening successively as the turret rotates. The retaining plate is rigidly mounted on the frame of the apparatus and is positioned such that the bottom surface of the turret sweeps across the top surface of the retaining plate.
The Partos U.S. Pat. No. 3,633,245 describes a machine for forming meatballs or the like which also has a rotary turret with bottom opening mold cavities and reciprocable pistons and a feeding mechanism for forcing meat upwardly into the mold cavities. In this machine the feeding mechanism has a discharge head with an upper plate which engages the lower surface of the rotating turret. The upper plate of the discharge head is forced upwardly against the lower surface of the turret by a series of levelling studs coacting between the discharge head and the supporting framework of the machine.